The effects of the history in strain-amplitude and temperature variation on the multiaxial cyclic behavior of type 316 stainless steel were discussed by performing a series of total-strain controlled cyclic tests under uniaxial tension-compression and circular strain paths. Constant strain rate of 0.2 percent/min was specified throughout the tests. The effects of strain amplitude history were examined by changing the strain amplitude between 0.2 percent and 0.4 percent (step-up and step-down tests) at room temperature, 400°C and 600°C. For temperature history dependence tests, the temperature was changed between 200°C and 600°C, 400°C and 600°C, 500°C and 600°C, by specifying a constant strain amplitude of 0.3 percent. It was observed that for the step-up change in strain amplitude the prior cycle showed apparently no influence on the subsequent cyclic accommodation for the uniaxial and the multiaxial cycles at room temperature, 400°C and 600°C. For the decrease in strain amplitude, however, the definite effect of the prior cycle was observed at 400°C, while at higher temperature it disappeared. The effect of the temperature history, on the other hand, appeared only in the case of the temperature-decrease during the uniaxial cycle.

Temperature dependence of multiaxial cyclic behavior of type 316 stainless steel was elucidated experimentally. Cyclic tests under constant total-strain amplitudes were performed for uniaxial tension-compression and circular (non-proportional) strain paths at several temperatures; room temperature, 200°C, 400°C, 500°C, 600°C, and 700°C. The strain amplitudes of the cycles were specified to be 0.2, 0.3, and 0.4 percent under constant strain rate of 0.2 percent per min. A quantitative discussion was made with special emphasis on the difference between material behavior under uniaxial tension-compression strain cycles and multiaxial non-proportional circular ones at these temperatures. The most significant cyclic hardening was observed in the temperature range between 400°C and 600°C for both the proportional and the non-proportional strain cycles. At these particular temperatures, much larger inelastic strain was accumulated until a cyclic stabilization was obtained. Though the effect of non-proportionality in the cyclic strain paths on the cyclic hardening was significant particularly at the temperature below 450°C, it rapdily decreased at higher temperatures.

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